Eliminate some repetition in the setting

[masak]

I just caught sight of this in the setting code:

abs      => -> $arg { Val::Int.new(:value($arg.value.abs)) },
min      => -> $a, $b { Val::Int.new(:value(min($a.value, $b.value))) },
max      => -> $a, $b { Val::Int.new(:value(max($a.value, $b.value))) },
chr      => -> $arg { Val::Str.new(:value($arg.value.chr)) },
ord      => -> $arg { Val::Int.new(:value($arg.value.ord)) },
chars    => -> $arg { Val::Int.new(:value($arg.value.Str.chars)) },
uc       => -> $arg { Val::Str.new(:value($arg.value.uc)) },
lc       => -> $arg { Val::Str.new(:value($arg.value.lc)) },
trim     => -> $arg { Val::Str.new(:value($arg.value.trim)) },
elems    => -> $arg { Val::Int.new(:value($arg.elements.elems)) },
reversed => -> $arg { Val::Array.new(:elements($arg.elements.reverse)) },
sorted   => -> $arg { Val::Array.new(:elements($arg.elements.sort)) },
join     => -> $a, $sep { Val::Str.new(:value($a.elements.join($sep.value.Str))) },
split    => -> $s, $sep { Val::Array.new(:elements($s.value.split($sep.value))) },
index    => -> $s, $substr { Val::Int.new(:value($s.value.index($substr.value) // -1)) },
substr   => sub ($s, $pos, $chars?) { Val::Str.new(:value($s.value.substr($pos.value, $chars.defined ?? $chars.value !! $s.value.chars))) },

Clearly we're manually wrapping a lot of these in the right Val type. How about we do that automatically once and for all somewhere, instead of in every single subroutine?

• The easy way: define a wrap which does the right thing for the various Val types, and call it everywhere. Would still make things shorter.
• The HOP way: define a wrap which takes a function that returns a Perl 6 value and returns a function that returns an appropriate Val value. Call it once from the loop that put-vars everything in the setting.

Oh, and I noticed two bugs while I was in there:

say      => -> $arg { self.output.say(~$arg) },
type     => sub ($arg) { return 'Sub' if $arg ~~ Val::Sub; $arg.^name.substr('Val::'.chars) },

type returns a Str, not a Val::Str. The HOP way mentioned above would make this implementation right without any further changes. say should proabably return None, but right now it is likely to return a Perl 6 Bool, because that's what $*OUT.say returns:

$ perl6 -e 'say (say "hi").^name'
hi
Bool